Rotate around point and scale

[AlexEdunov]

Hello. Thanks for a great work.

I'd like to implement some additional functionality. I want user to interact with view by pinch and rotate gestures. I've implemented it.

var initialQuadrilateral: AGKQuad?

@IBAction func handlePinch(_ recognizer : UIPinchGestureRecognizer) {
    if (recognizer.state == .began) {
        initialQuadrilateral = target.layer.quadrilateral
    }
    
    let transform = CGAffineTransform.identity.scaledBy(x: recognizer.scale, y: recognizer.scale)
    target.layer.quadrilateral = AGKQuadApplyCGAffineTransform(initialQuadrilateral!, transform)
    
    updateControlPoints()
}

@IBAction func handleRotation(_ recognizer : UIRotationGestureRecognizer) {
    if (recognizer.state == .began) {
        initialQuadrilateral = target.layer.quadrilateral
    }
    
    target.layer.quadrilateral = AGKQuadRotateAroundPoint(initialQuadrilateral!, target.frame, recognizer.rotation)
    
    updateControlPoints()
}

The only problem is that view rotates and scales around zero anchor point instead of center. Could you provide an example of how to implement expected behavior.

[hfossli]

Does this happen both on pinch and rotation? or just pinch?

[AlexEdunov]

I've created an example to show what is really happening. Please take a look: https://github.com/AlexEdunov/AGGeometryKitIssue

[hfossli]

Cool. Example projects are 👌

Sent you a pull request https://github.com/AlexEdunov/AGGeometryKitIssue/pull/1

Not the prettiest code, but it seemed to work on my end.